Posted
by
ScuttleMonkeyon Monday February 09, 2009 @04:34PM
from the high-tech-to-the-lowest-bid dept.

pha7boy writes "The Herschel space observatory, the European Space Agency's answer to the Hubble Telescope, is about to be sent into orbit. With a mirror 1.5 times the size of the Hubble mirror, the Herschel will look at the universe in the infrared and sub-millimeter range. This 'will permit Herschel to see past the dust that scatters Hubble's visible wavelengths, and to gaze at really cold places and objects in the Universe — from the birthing clouds of new stars to the icy comets that live far out in the Solar System.'"

I think Hubble has been one of the most interesting and successful space based missions ever. A lot of the most mind blowing images I've ever seen of space have come from that telescope. Hopefully this telescope will continue the trend.

As for all the new discoverys i'm sure these new telescopes will find, i'm curious if they will do the same thing with these as they did with the hubble, by pointing it at a "black" region of space and leaving it there for a while gathering exposures, only to discover that the region wasn't "black" at all, it was completely filled with all sorts of different galaxies, and this was only a small point in space they were looking.

Given the additional 1m on the reflector, it'd be safe to assume a far better performance than Hubble.

Yep. Meters matter. A lot. The summary says the mirror is 1.5 times as big (3.5m/2.4m), but really area and thus quantity of incident light is what matters so it's more like 210% as big as Hubble (3.5^2)/(2.4^2). This is a big space telescope. All else being the same, I'd expect this to show a good deal more distant/faint objects.

It says it's infrared, so this may be more comparable to Spitzer than Hubble. Spitzer is only 0.85m. This beast is 17 times the light bucket Spitzer is.

It depends what you're comparing. Hubble looks a bit into the near IR too. Spitzer is mostly mid-IR, and Herschel is designed to look at very long wave IR and the higher frequency microwave region. Herschel and Spitzer overlap in wavelength a little bit, but not really that much.

In terms of application, Spitzer is not in the same sensitivity class as Hubble or Herschel, so for really deep field imaging the comparison between Hubble and Herschel is fairly apt.

Due note too, that the James Webb Space Telescope (the US's next telescope slated to launch in 2013, assuming funding doesn't dry up) is slated to have a 6.5m mirror, which should produce some REALLY nice results.

Adaptive optics help cancel out the distortions produced by the atmosphere. That's not particularly useful on a space telescope.

Once you've got adaptive optics to take away most of the biggest advantages for space telescopes, the ease of building giant mirrors on the ground takes over and you get much better performance for your budget.

Depends on what your goal is. However, you are correct in this matter.

Yes, AO is generally a specific application of a telescopic array designed to thwart distortions caused by an atmosphere. I should have been a bit more clear on this. In this case, I was mixing up AO with a composite mirror/detector telescope.

However, imagine an array much larger than we could build on the ground. For instance, multiple telescopes in orbit around the moon, earth, and the sun? You could use that for all sorts of interesting research (is there an application for multiple parallaxes?), but you could get a hell of a lot of resolution with an array the size of 2AU diameter (for instance, multiple telescopes in an earthlike orbit.)

In addition to that, the JWST will feature a micro-shutter array, composed of over 62,000 individual shutters in the area of a postage stamp. The idea is that each shutter can be independently opened and closed so visible light from near, bright objects can be blocked out making it easier to view objects that are further away.

I had the opportunity to tour the clean room at Goddard Space Flight Center where the array is being fabricated. The techniques used seemed to mirror the techniques used to manufacture modern microprocessors. It was very interesting to be guided through the process, there are definitely some incredibly smart people at Goddard.